Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class

Examples

Example 1 (i)

Example 1 (ii)

Example 2

Example 3 Important

Example 4

Example 5 Important

Example 6

Example 7 Important

Example 8

Example 9 Important

Example 10 Important

Example 11

Example 12 Important

Example 13 Important

Example 14

Question 1 Deleted for CBSE Board 2024 Exams

Question 2 Deleted for CBSE Board 2024 Exams

Question 3 Important Deleted for CBSE Board 2024 Exams

Question 4 Deleted for CBSE Board 2024 Exams You are here

Question 5 Important Deleted for CBSE Board 2024 Exams

Question 6 Important Deleted for CBSE Board 2024 Exams

Question 7 Deleted for CBSE Board 2024 Exams

Question 8 Important Deleted for CBSE Board 2024 Exams

Question 9 Deleted for CBSE Board 2024 Exams

Question 10 Important Deleted for CBSE Board 2024 Exams

Chapter 8 Class 11 Sequences and Series

Serial order wise

Last updated at May 29, 2023 by Teachoo

Question 4 The income of a person is Rs. 3,00,000, in the first year and he receives an increase of Rs.10,000 to his income per year for the next 19 years. Find the total amount, he received in 20 years. Income of the person in 1st year = Rs 3,00,000 Income of the person in 2nd year = Rs 3,00,000 + 10,000 = Rs 3,10,000 Income of the person in 3rd year = Rs 3,10,000 + 10,000 = Rs 3,20,000 Thus, Income received every year is 300000, 310000, 320000, This is an A.P as difference between consecutive terms is constant. 300000, 310000, 320000, Here first term = a = 300000 common difference = d = 310000 300000 = 10000 To find the total amount received in 20 years, we use the formula Sn = n/2 ( 2a + (n 1)d ) Where, Sn = sum of n terms of A.P. n = number of terms a = first term and d = common difference Here, Sn = Amount received in 20 years, n = 20 , a = 300000, d = 10000 Putting the values S20= 20/2 [2 300000 + (20 1)10000] S20= 20/2 [2 300000 + (20 1)10000] = 10 [ 600000 + 19 10000] = 10 [600000 + 190000] = 10 (790000) = 79,00,000 Thus , the total amount received at the end of 20 years is Rs. 79,00,000.